A technology of appropriately extracting character pixels configuring a character by using target image data representing a target image including the character is needed. For example, binary data indicative of the extracted character pixels can be efficiently used for compression of the target image data, specifically, for generation of a so-called highly compressed PDF file. In this technology, binary data indicative of character pixels are generated using a character color value, a background color value and a feature value relating to sharpness of a character in a target image.
However, according to the above technology, since information to be considered for extraction of the character pixels is not sufficient, there is a possibility that the character pixels cannot be extracted with high precision.